Thermal Power Unit Dual Pressure Condenser Heating Technology Research

It is universally acknowledged that regardless of how large the capacity of the condensing unit the final exhaust contains a huge amount of waste heat,but in the end this part of the amount of heat released through the cooling tower to the environment and the unit and the ecological impact of the environment.On the one hand exhaust heat waste is inevitably wasted resulting in low efficiency,on the other hand will contribute to the thermal pollution of the atmospheric environment.Furthermore,how to use this part of the remaining heat has become the focus of attention.The high back pressure heating of pure condensing turbine can effectively recover the waste heat of exhaust steam,and it can meet the great demand of heat supply by building circulating water system of circulating network to utilize the waste heat to heat the circulating water.The use of high back pressure heating unit can not only improve the unit's thermal efficiency,thermal economy and improve energy efficiency,but also reduce or eliminate the exhaust heat on the ecological environment of thermal pollution,bring some social benefits.In this paper,a 600 MW subcritical and once intermediate reheat unit of a power plant is taken as the research object,and a N39000-2 surface type double-pressure condenser is equipped.According to the characteristics of selected unit operation,the scheme of retrofitting high-back-pressure heat supply of double-pressure condenser was designed,and the maximum heat load operation condition was selected to quantitatively analyze the economic and safety.The results show that the modified scheme is safe and feasible.After the feasibility of the retrofit scheme is determined,the equivalent enthalpy drop method is adopted as the basic method to study the operating characteristics of the variable-duty unit.Under the condition of the new steam flow rate unchanged,the analysis and comparison of the pro-and post-the optimum vacuum determination method based on pure condensing steam condition is proposed.The optimal vacuum method for high back pressure heating conditions are better than the pure condensing steam operating conditions in different heating periods.Through optimizing the operation of high back pressure heating,the unit economy can be improved.